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			扩展QML -添加类型示例</td></tr></table><table class="buildversion"><tr>
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<h3><a name="toc">目录</a></h3>
<ul>
<li class="level1"><a href="#declare-the-person-class">Declare the Person Class</a></li>
<li class="level1"><a href="#define-the-person-class">Define the Person Class</a></li>
<li class="level1"><a href="#running-the-example">运行该示例</a></li>
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<h1 class="title">扩展QML -添加类型示例</h1>
<span class="subtitle"></span>
<!-- $$$referenceexamples/adding-brief -->
<p>导出C++类。</p>
<!-- @@@referenceexamples/adding -->
<!-- $$$referenceexamples/adding-description -->
<div class="descr"> <a name="details"></a>
<p>添加类型示例展示了如何向QML添加新的对象类型Person。Person类型可以像这样从QML中使用:</p>
<pre class="qml">

  import People 1.0

  <span class="type">Person</span> {
      <span class="name">name</span>: <span class="string">&quot;Bob Jones&quot;</span>
      <span class="name">shoeSize</span>: <span class="number">12</span>
  }

</pre>
<a name="declare-the-person-class"></a>
<h2 id="declare-the-person-class">声明Person类</h2>
<p>所有QML类型都映射到C++类型。在这里，我们声明了一个基本的C++ 
Person类，其中包含我们希望在QML类型上访问的两个属性——name和shoeSize。尽管在本例中，我们使用了与QML类型相同的C++类名称，但是C++类可以以不同的方式命名，或者出现在一个名称空间中。</p>
<pre class="cpp">

  <span class="keyword">class</span> Person : <span class="keyword">public</span> <span class="type"><a href="../qtcore/qobject.html">QObject</a></span>
  {
      Q_OBJECT
      Q_PROPERTY(<span class="type"><a href="../qtcore/qstring.html">QString</a></span> name READ name WRITE setName)
      Q_PROPERTY(<span class="type">int</span> shoeSize READ shoeSize WRITE setShoeSize)
  <span class="keyword">public</span>:
      Person(<span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent <span class="operator">=</span> <span class="number">0</span>);

      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> name() <span class="keyword">const</span>;
      <span class="type">void</span> setName(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>);

      <span class="type">int</span> shoeSize() <span class="keyword">const</span>;
      <span class="type">void</span> setShoeSize(<span class="type">int</span>);

  <span class="keyword">private</span>:
      <span class="type"><a href="../qtcore/qstring.html">QString</a></span> m_name;
      <span class="type">int</span> m_shoeSize;
  };

</pre>
<a name="define-the-person-class"></a>
<h2 id="define-the-person-class">定义Person类</h2>
<pre class="cpp">

  Person<span class="operator">::</span>Person(<span class="type"><a href="../qtcore/qobject.html">QObject</a></span> <span class="operator">*</span>parent)
  : <span class="type"><a href="../qtcore/qobject.html">QObject</a></span>(parent)<span class="operator">,</span> m_shoeSize(<span class="number">0</span>)
  {
  }

  <span class="type"><a href="../qtcore/qstring.html">QString</a></span> Person<span class="operator">::</span>name() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> m_name;
  }

  <span class="type">void</span> Person<span class="operator">::</span>setName(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&amp;</span>n)
  {
      m_name <span class="operator">=</span> n;
  }

  <span class="type">int</span> Person<span class="operator">::</span>shoeSize() <span class="keyword">const</span>
  {
      <span class="keyword">return</span> m_shoeSize;
  }

  <span class="type">void</span> Person<span class="operator">::</span>setShoeSize(<span class="type">int</span> s)
  {
      m_shoeSize <span class="operator">=</span> s;
  }

</pre>
<p>Person类实现非常基础。属性访问器只是返回对象实例的成员。</p>
<p>
main.cpp文件还调用qmlRegisterType()函数以将Person类型注册为People库1.0版本中的类型，并定义C++和QML类名之间的映射。</p>
<a name="running-the-example"></a>
<h2 id="running-the-example">运行这个例子</h2>
<p>示例中的main.cpp文件包含一个简单的shell应用程序，该应用程序加载并运行本页开头显示的QML代码片段。</p>
<p><span lang="zh-cn">文件：</span></p>
<ul>
<li><a href="qtqml-referenceexamples-adding-adding-pro.html">referenceexamples/adding/adding.pro</a></li>
<li><a href="qtqml-referenceexamples-adding-adding-qrc.html">referenceexamples/adding/adding.qrc</a></li>
<li><a href="qtqml-referenceexamples-adding-example-qml.html">referenceexamples/adding/example.qml</a></li>
<li><a href="qtqml-referenceexamples-adding-main-cpp.html">referenceexamples/adding/main.cpp</a></li>
<li><a href="qtqml-referenceexamples-adding-person-cpp.html">referenceexamples/adding/person.cpp</a></li>
<li><a href="qtqml-referenceexamples-adding-person-h.html">referenceexamples/adding/person.h</a></li>
</ul>
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